rrc-nr,test: add security_cmd helper test

Signed-off-by: Carlo Galiotto <carlo@srs.io>

srsgnb/src/stack/rrc/rrc_nr.cc

@@ -495,10 +495,13 @@ void rrc_nr::handle_ul_dcch(uint16_t rnti, uint32_t lcid, srsran::const_byte_spa
       break;
     case ul_dcch_msg_type_c::c1_c_::types_opts::security_mode_complete:
       u.handle_security_mode_complete(ul_dcch_msg.msg.c1().security_mode_complete());
+      break;
     case ul_dcch_msg_type_c::c1_c_::types_opts::rrc_recfg_complete:
       u.handle_rrc_reconfiguration_complete(ul_dcch_msg.msg.c1().rrc_recfg_complete());
+      break;
     case ul_dcch_msg_type_c::c1_c_::types_opts::ul_info_transfer:
       u.handle_ul_information_transfer(ul_dcch_msg.msg.c1().ul_info_transfer());
+      break;
     default:
       log_rx_pdu_fail(rnti, srb_to_lcid(lte_srb::srb0), pdu, "Unsupported UL-CCCH message type", false);
       // TODO Remove user

srsgnb/src/stack/rrc/test/rrc_nr_test.cc

@@ -165,6 +165,7 @@ void test_rrc_sa_connection()
   TESTASSERT_SUCCESS(rrc_obj.add_user(0x4601, uecfg));
 
   test_rrc_nr_connection_establishment(task_sched, rrc_obj, rlc_obj, 0x4601);
+  test_rrc_nr_security_mode_cmd(task_sched, rrc_obj, pdcp_obj, 0x4601);
 }
 
 } // namespace srsenb

srsgnb/src/stack/rrc/test/rrc_nr_test_helpers.cc

@@ -24,7 +24,7 @@ void test_rrc_nr_connection_establishment(srsran::task_scheduler& task_sched,
 {
   srsran::unique_byte_buffer_t pdu;
 
-  // Send RRCSetupRequest
+  // Step 1 - Send RRCSetupRequest (UE -> gNB)
   ul_ccch_msg_s            setup_msg;
   rrc_setup_request_ies_s& setup  = setup_msg.msg.set_c1().set_rrc_setup_request().rrc_setup_request;
   setup.establishment_cause.value = establishment_cause_opts::mo_data;
@@ -36,17 +36,23 @@ void test_rrc_nr_connection_establishment(srsran::task_scheduler& task_sched,
     pdu->N_bytes = bref.distance_bytes();
   }
 
+  // Pass message to RRC
   rrc_obj.write_pdu(rnti, 0, std::move(pdu));
   task_sched.tic();
 
+  // Step 2 - RRCSetup (gNB -> UE)
+  // The response to RRCSetupRequest has been sent by RRC - check if this message (RRCSetup) is correct
   TESTASSERT_EQ(rnti, rlc.last_sdu_rnti);
   TESTASSERT_EQ(srsran::srb_to_lcid(srsran::nr_srb::srb0), rlc.last_sdu_lcid);
   TESTASSERT(rlc.last_sdu->size() > 0);
+
+  // dl_ccch_msg will store the unpacked RRCSetup msg sent by the RRC
   dl_ccch_msg_s dl_ccch_msg;
   {
     asn1::cbit_ref bref{rlc.last_sdu->data(), rlc.last_sdu->size()};
     TESTASSERT_SUCCESS(dl_ccch_msg.unpack(bref));
   }
+  // Test if the RRC sent the correct RRCSetup msg
   TESTASSERT_EQ(dl_ccch_msg_type_c::types_opts::c1, dl_ccch_msg.msg.type().value);
   TESTASSERT_EQ(dl_ccch_msg_type_c::c1_c_::types_opts::rrc_setup, dl_ccch_msg.msg.c1().type().value);
   TESTASSERT_EQ(rrc_setup_s::crit_exts_c_::types_opts::rrc_setup,
@@ -59,6 +65,7 @@ void test_rrc_nr_connection_establishment(srsran::task_scheduler& task_sched,
   const srb_to_add_mod_s& srb1 = setup_ies.radio_bearer_cfg.srb_to_add_mod_list[0];
   TESTASSERT_EQ(srsran::srb_to_lcid(srsran::nr_srb::srb1), srb1.srb_id);
 
+  // Step 3 - RRCSetupComplete (UE -> gNB) - Configure the msg and send it to RRC
   ul_dcch_msg_s         ul_dcch_msg;
   rrc_setup_complete_s& complete         = ul_dcch_msg.msg.set_c1().set_rrc_setup_complete();
   complete.rrc_transaction_id            = dl_ccch_msg.msg.c1().rrc_setup().rrc_transaction_id;
@@ -80,4 +87,50 @@ void test_rrc_nr_connection_establishment(srsran::task_scheduler& task_sched,
   rrc_obj.write_pdu(rnti, 1, std::move(pdu));
 }
 
+void test_rrc_nr_security_mode_cmd(srsran::task_scheduler& task_sched,
+                                   rrc_nr&                 rrc_obj,
+                                   pdcp_nr_rrc_tester&     pdcp,
+                                   uint16_t                rnti)
+{
+  srsran::unique_byte_buffer_t pdu;
+
+  // Test whether there exists the SRB1 initiated in the Connection Establishment
+  // We test this as the SRB1 was setup in a different function
+  TESTASSERT_EQ(rnti, pdcp.last_sdu_rnti);
+  TESTASSERT_EQ(srsran::srb_to_lcid(srsran::nr_srb::srb1), 1);
+
+  // Send SecurityModeCommand (gNB -> UE)
+  dl_dcch_msg_s dl_dcch_msg;
+  {
+    asn1::cbit_ref bref{pdcp.last_sdu->data(), pdcp.last_sdu->size()};
+    TESTASSERT_SUCCESS(dl_dcch_msg.unpack(bref));
+  }
+  TESTASSERT_EQ(dl_dcch_msg_type_c::types_opts::c1, dl_dcch_msg.msg.type().value);
+  TESTASSERT_EQ(dl_dcch_msg_type_c::c1_c_::types_opts::security_mode_cmd, dl_dcch_msg.msg.c1().type().value);
+  TESTASSERT_EQ(security_mode_cmd_s::crit_exts_c_::types_opts::security_mode_cmd,
+                dl_dcch_msg.msg.c1().security_mode_cmd().crit_exts.type().value);
+
+  security_mode_cmd_ies_s& ies = dl_dcch_msg.msg.c1().security_mode_cmd().crit_exts.security_mode_cmd();
+  TESTASSERT_EQ(true, ies.security_cfg_smc.security_algorithm_cfg.integrity_prot_algorithm_present);
+  TESTASSERT_EQ(integrity_prot_algorithm_opts::nia0,
+                ies.security_cfg_smc.security_algorithm_cfg.integrity_prot_algorithm.value);
+  TESTASSERT_EQ(ciphering_algorithm_opts::nea0, ies.security_cfg_smc.security_algorithm_cfg.ciphering_algorithm.value);
+
+  // Send SecurityModeComplete (UE -> gNB)
+  ul_dcch_msg_s ul_dcch_msg;
+  auto&         sec_cmd_complete_msg = ul_dcch_msg.msg.set_c1().set_security_mode_complete();
+  sec_cmd_complete_msg.rrc_transaction_id = dl_dcch_msg.msg.set_c1().security_mode_cmd().rrc_transaction_id;
+  auto& ies_complete                      = sec_cmd_complete_msg.crit_exts.set_security_mode_complete();
+
+  {
+    pdu = srsran::make_byte_buffer();
+    asn1::bit_ref bref{pdu->data(), pdu->get_tailroom()};
+    TESTASSERT_SUCCESS(ul_dcch_msg.pack(bref));
+    pdu->N_bytes = bref.distance_bytes();
+  }
+
+  // send message to RRC
+  rrc_obj.write_pdu(rnti, 1, std::move(pdu));
+}
+
 } // namespace srsenb

srsgnb/src/stack/rrc/test/rrc_nr_test_helpers.h

@@ -65,6 +65,11 @@ void test_rrc_nr_connection_establishment(srsran::task_scheduler& task_sched,
                                           rlc_nr_rrc_tester&      rlc,
                                           uint16_t                rnti);
 
+void test_rrc_nr_security_mode_cmd(srsran::task_scheduler& task_sched,
+                                   rrc_nr&                 rrc_obj,
+                                   pdcp_nr_rrc_tester&     pdcp,
+                                   uint16_t                rnti);
+
 } // namespace srsenb
 
 #endif // SRSRAN_RRC_NR_TEST_HELPERS_H